I have no inside information about Tyler Hamilton's guilt or innocence but you can count me as a knowledgeable person about laboratory medicine and blood banking who hates this blood doping test. With this McCarthyesque zeal to run the cheaters out of sport, we have approached the threshold of ruining the careers and lives innocent athletes with unproven testing technology.
I'm a pathologist with over 20 yr experience in laboratory medicine and blood banking and I can assure you that NO laboratory test is always accurate all the time. If everything were so foolproof in blood banking, why have hundreds of patients died of hemolytic transfusion reactions after receiving incompatible blood? In our business peoples lives are on the line when typing, cross-matching, and transfusing blood. But mistakes still occur every day. Where in the process are mistakes made? Every single step. Most errors are human--technical, clerical, interpretive, etc. But there are also faulty reagents and equipment.
Our hospital blood bank is inspected and certified by the FDA, the state health dept, Amer Assn of Blood Banks, Joint Commission of Amer Hospitals, and the College of American Pathologists. Rigorous policies, procedures, record keeping, quality control testing, proficiency testing, etc is required by each of these regulatory agencies. But mistakes are still made.
Who inspects and certifies WADA labs? Who manufactures and QA's their reagents and equipment. Who trains and certifies their personnel? How rigorously tested is this new anti-blood doping test. Who has established sensitivity and specificity levels? What exactly is the screen and the verification? Are fluorescent tagged RBCs viewed thru a fluorescent microscope or run thru a flow cytometer?
This is a test for a panel of non-ABO blood group antigens. I have seen plenty of cases where low titer or low affinity blood group antibodies and low epitope cell surface antigens have been detected by one technique in one laboratory and not with a different technique in another lab. Some of these could result in what we called, with somewhat outdated technology, a mixed field reaction, possibly suggesting two RBC populations. Most of these cases of weak or borderline positive minor blood group antigens/antibodies are of little clinical significance. But, as applied by the WADA labs, these possible false positives can ruin people.
There are other possible explanations for false positives. Some medications can bind to RBC membranes and can cross react with minor blood group antibodies. One could take such a (legal) medication which could bind to the RBCs in the circulation, stop the medication, and then in subsequent weeks have a "mixed" population of RBCs as un-drug bound RBCs enter the circulation. There are a variety of medications and other "artifacts" which cause all kinds of problems in blood bank testing and transfusion medicine.
How objective and professionally responsible are the people who developed and implemented these tests? From
http://www.cyclingnews.com/news.php?id=features/2004/blood_doping
:
Dr Michael Ashenden (project coordinator for the research consortium Science and Industry Against Blood doping, and one of the scientists responsible for developing the new technique) is a man on a mission, and that mission is a very straightforward one: the eradication of blood doping, which he describes as "the most diabolical form of doping....It has to be stamped out....It's repugnant"
Diabolical? Get a grip. No wonder this guy has deemed his test 100% sensitive and 100% specific with no possibility of false positives or negatives. Yes, he's on a mission. And Tyler Hamilton and anyone else who was (possibly) born with an unusual minor blood group antigen or had some other justifiable scientific reason for testing positive without cheating had better get the hell out of his way.
There's just too much at stake. I fear that these shrill anti-doping zealots have clouded our collective judgment and allowed the application of testing which has not been adequately validated. As I said, no laboratory test is 100% accurate. In medicine we never say "always" and we never say "never". Before we string up Hamilton as the first to fail this test, isn't it fair to ask if the test and the testers have been adequately tested?
Dr. PB